title: In vitro selection of a DNA aptamer targeted against Shigella dysenteriae.
abstract: To identify DNA aptamers demonstrating binding specificity for Shigella dysenteriae, a whole-bacterium Systemic Evolution of Ligands by Exponential enrichment (SELEX) method was applied to a combinatorial library of single-stranded DNA (ssDNA) molecules. After several rounds of selection using S. dysenteriae as the target, the highly enriched oligonucleotide pool was sequenced and then grouped into different families based on primary sequence homologies and similarities in the secondary structures. Aptamer S 1, which showed particularly high binding affinity in preliminary studies, was chosen for further characterisation. This aptamer displayed a dissociation constant (Kd value) of 23.47 ± 2.48 nM. Binding assays to assess the specificity of aptamer S 1 showed high binding affinity for S. dysenteriae and low apparent binding affinity for other bacteria. The ssDNA aptamers generated may serve as a new type of molecular probe for microbial pathogens, as it has the potential to overcome the tedious isolation and purification requirements for complex targets.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Nuo
authors.initials: N
authors.lastname: Duan
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Ding
authors.forename: Shijia
authors.initials: S
authors.lastname: Wu
authors.forename: Yu
authors.initials: Y
authors.lastname: Xia
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Ma
authors.forename: Zhouping
authors.initials: Z
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001431:Bacteriological Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000737:chemistry; D057230:Limit of Detection; D016014:Linear Models; D009690:Nucleic Acid Conformation; D052156:SELEX Aptamer Technique / Q000379:methods*; D012762:Shigella dysenteriae / Q000302:isolation & purification*
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded
keywords: Application; Aptamer; SELEX; Shigella dysenteriae